1. Field of Invention
The present invention relates to a cannulated tubular instrument for access and visualization of body tissues. The apparatus aids insertion of catheters and other instruments into the body of a patient and can be used in combination with a trochar inserted into its lumen to bluntly dissect obstructing tissues before placement of the implement. Additionally, the instrument includes multiple apertures on its distal portion to facilitate visual and physical access to target body tissues.
2. Background of the Invention
The use of a cannula, sheath, or director to guide or ease insertion of surgical instruments or to facilitate access to a surgical field is well known. In addition, a rigid trochar or trochar-like assembly is often included that can be inserted into the cannula to bluntly dissect tissues during insertion of the device.
For example, U.S. Pat. No. 5,545,136 issued Aug. 13, 1996, a patent issued to the present inventor, discloses a surgical instrument used in the treatment of carpal tunnel syndrome having a rigid tubular member with lumen through which a balloon carpal tunnel plasty procedure may be undertaken. The balloon expands through an aperture in the radial wall of the tubular member and the tubular member includes a rigid, solid rounded tip to ease insertion of the apparatus into the carpal tunnel. Other instruments are then used in conjunction with the instrument to perform the surgery. U.S. Pat. No. 6,706,069 issued Mar. 16, 2004, also to the present inventor, is directed toward a grooved director with a built in balloon which is inflated by a pump to a predetermined pressure to expand the walls of a collapsed vertebra. The device is inserted into the body of the compressed vertebra and the grooved director is positioned and aimed in a direction under the compressed superior end plate of the vertebral body. The balloon inside of the grooved director is inflated and the force and direction of balloon inflation restores the height of the fractured vertebrae. The balloon is deflated and the grooved director is circumferentially rotated while intermittently inflating and deflating the balloon to create a symmetrical space within the center of the vertebral body. The balloon is deflated and the grooved director device with balloon is removed leaving a rebuilt vertebra which may be filled with a biocompatible material. U.S. Pat. No. 4,655,214 issued Apr. 7, 1987 shows a soft inflatable sheath having a closed rounded distal tip that is inserted through a catheter and inflated adjacent the distal tip of the catheter prior to intubation. The proximal end of the sheath is sealed to maintain it in an expanded condition when the catheter is being intubated. Following intubation the cylindrical sheath is deflated and withdrawn U.S. Pat. No. 4,645,491 issued Feb. 24, 1987 shows a catheter placement apparatus used in inserting a catheter to a preferred depth. The device comprises a surgical needle provided with a thin-walled transparent polytetrafluoroethylene tube which is heat shrunk over the stem portion of the needle to form a longitudinal window allowing a catheter inserted in the needle to be viewed. The catheter has a colored patch of the same length as the window and a series of spaced circular bands of differing colors allowing the position of the catheter to be accurately located by lining the colored patch with the window and advancing the catheter until at least one band appears in the window. The color and distance of the band nearest to the surface of the patient's skin are used to determine the position of the catheter. The surgical needle is withdrawn by sliding it along and off the catheter. U.S. Pat. No. 2,164,926 issued Jul. 4, 1939 shows a catheter stylet with an eye or aperture positioned on an opposite lateral wall behind the tip. U.S. Pat. No. 3,537,452 issued Nov. 3, 1970 shows a needle guard and beveled cutter for use with intravenous catheterization units. The device has a tubular body with a flat base and a longitudinally slotted top. The diameter of the tube is greater than the diameter of the needle contained therein. U.S. Pat. No. 3,592,193 issued Jul. 13, 1971 shows a removable needle guide used with a flexible catheter tube in withdrawing or introducing fluids relative to a body. The hollow tubular needle guide has a sharpened needle portion provided at its proximal end for puncturing the skin, tissues and veins of the body where the needle is inserted. At its distal end, the guide has winged handles which provide controlled insertion and removal from the body with subsequent attachment from a flexible catheter tube. U.S. Pat. No. 5,011,478 issued Apr. 30, 1991 shows an introducer set including a sheath and dilator formed with a smooth external shape. The distal end of the sheath is embedded in the dilator and formed in angle oblique to the longitudinal access of the introducer set. U.S. Pat. No. 3,559,643 issued Feb. 2, 1971 shows a catheter placement unit for insertion of a catheter into a body lumen through an incised opening in the lumen wall. The unit includes a longitudinally slit sheath having a catheter therein and an advancer connected to one end of the catheter, initially in axial alignment with the sheath to close the end of the sheath.
There is presently a need, however, for an orthopedic and general surgical manual instrument that combines various features of these multiple instruments. Such an instrument is usable as a combination director, probe, cannula, elevator, flexible arthroscope/endoscope laser guide, and cutting guide for orthopedic and general surgery. Now a common component of many surgical procedures, arthroscopes and endoscopes utilize fiber optic technology to allow the surgeon to visualize interior tissues through a small incision. Rigid arthroscopes and endoscopes have visual fields limited by the angle of their lens. Conversely, flexible arthroscopes/endoscopes enable the surgeon to visualize multiple angle locations during surgery but the flexibility which makes them more useful in visualizing the surgical site also makes them difficult to position due to the resistance of the tissues being examined. Inserting the flexible arthroscope/endoscope into a cannula of the present invention facilitates positioning in the body and provides protection for the device.